The concept of continuous motion in-line sealers for sealing foils to containers is known in the art. For example, U.S. Pat. No. 4,816,110 shows a sealing system that includes a rotateable turret that has a pocket wheel to hold containers. Associated with the rotateable turret is a foil transfer and sealing mechanism that uses an induction heater to seal the foil cover to the container. In contrast, the present system includes a postionable filling device to fill the container, a flying punch to form a cover seal and an induction sealing mechanism to seal the cover seal to the container in one continuous operation.
The concept of induction heating is well known in the sealing art and is used to seal metal foil covers to containers. Typically, in induction heating an electrical conducting material, such as a the foil cover with a hot-melt adhesive, is placed in a varying magnetic field which heats the electrical conducting material to melt the adhesive. In the container art, induction heating is a preferred method as one can quickly secure an electrical conducting foil cover to a container by inductively heating the foil cover to melt or soften an adhesive located on the cover. When the adhesive is heated to a condition for adhesively bonding the cover seal to the container, the cover seal and container are maintained in contact with one another to allow the adhesive to set and adhesively secure the cover seal to the container.
One of the difficulties with induction heating and filling is that the filling and the sealing are done in separate regions which require transferring a filled container across some interface before the cover seal can be sealed to the container. The transfer inevitably involves jostling the container which can cause spilling of the contents of the container. To minimize spillage problems the containers are usually only partially prefilled. The present invention provides a method and apparatus for filling a container and sealing a cover seal to a container that allows the containers to be filled and handled without the jostling that might spill the contents of the container. In addition, there is no relative motion between the cover-seal holding mechanism and the elevator platforms supporting the containers during both the heating and the cooling.
The present invention provides an apparatus for on-the-go filling a container, on-the-go forming of a cover seat and on-the-go sealing of a cover seal to the container in a continuous operation through a rotating head that carries a traveling punch and a set of postionable filling spouts. The system includes cam-controlled elevator platforms that maintain the containers in a position for low splash filling and, after the filling process is complete, the elevator platforms maintain the cover seals in pressure engagement with the containers, so that the cover seals can be inductively sealed to the containers by an induction-sealing apparatus located above the rotating head.